In cryptographic applications, for example, large numbers are used as a security or encryption key for encrypting information and messages.
For processing such large numbers, a large number processing/arithmetic circuit is used, which performs several arithmetic operations in sequence under control of a control unit using operands of a specific length. These operands and the results of the arithmetic operations are frequently stored and read from different memory locations, as specified by the control unit.
The operands used for processing large numbers also have a rather long length of digital bits, thus requiring a significant amount of space in the memory unit. The control unit, for controlling the large number generator circuit, requires considerable computing time reading such large numbers from and writing such large numbers to the memory unit.